SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c945bdcef39f1034adebc880ddfebe6c03267ddeb1443686df68965f33aa33be' 
  AND token = '+ph8SmXFe6P/B56sxZKBcFclgpogiw31sB/dLy98fA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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