SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e97eb996ef31caf1d9d82ec5b71fd00a94f644314d46280e2263466c28b0dfb5' 
  AND token = 'Fem3vFo5o1LH+chRZnXtReh4/8DUwr0uj3PIAwLptGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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