SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a110177accb683bfe3623f86afe9915fb60a86ba7f8491807295a34995ba34cf' 
  AND token = 'iiUzgaPJHB8m8EtNSLABj9mlDMxzCMw9Yu44lui7itk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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