SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9436f015ef93a02b81aa71ecaeb1b27058b126ab35832844dca14b47d942bc18' 
  AND token = '8tKey38q4Z8F6pdrwWYl4VCCHzlJV6hX/K9q1WR+XXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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