SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29fa116ce44cad3141d21dc01c0dd29036881859a351eb60f09915354e7a615b' 
  AND token = 'osAgijwu0P6BIvqUNX1U+z330gu0HEtQFIxlHEzTBx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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