SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '528b3d8082e5871ed027b5a8b7a8a93607f329954fb83d274cfcc6e8783207c3' 
  AND token = 'fNAMX/VzATJtLI8iRXOm7rOFDGFB4zXF7jvSQ4BzdlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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