SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e9da56acf748ca32d8d1f1e13968500a41f5f2be8b11f268f8114c38757bc0a' 
  AND token = 'fcNNwLfcFmdvPIov7nvN6zEXF9PeuPMSZvMsyXWRRO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}