SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20e26821fb9b31652d30f8919c89d2af4f7f4822c1d9af6268329c9c5fa36dc4' 
  AND token = 'Uj9It7qW72OmefSwob2z3ESwMDkhvr9zGPKIiJ2GZjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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