SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a92869618d67b9ed847b7eb4e3fc6fdf3ee1856e93ecdff5cdd5059b48e8386e' 
  AND token = 'dbcYaKNgh8OHTBQFjoAA1i7RRkpkVaKZBNkoTqqD8uM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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