SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cbf1f490a905ede58d5f611b28747b0b506e978a8c641601df3a098b67e696d' 
  AND token = 'etuKWnE+WkEFg9O4oDibcV4jV7sfyvf2CeUfSEbqJxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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