SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b9c2b4cc5fdae77209ca2fd97896ef0852238dfd91644e9a9182e5450889953' 
  AND token = 'I92N/p31uiMkaYPpQ/UZfr4sAaTP4Eqi4tZrgox9Xp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}