SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d3f0dedffa4f0482c4df39fc672bf59c971e05cbd8bc09d7185085b298bb659' 
  AND token = 'NC9qVVUj8apQhSLBxUQv+cLRSfiXm1Cs6qmIkecQHyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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