SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0a57ece57d6ce13ff6b2b73db4cadf25d0115297aaf5d43766b935ebcc3a3e1' 
  AND token = 'BgO0aiI0eiXjOLdJu3t52Uoj+FYl204TzMC631jVeYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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