SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4df91087202bbf761f0576174e4f11dedefd8afd58d9b43724df5b59758aa1e5' 
  AND token = 'viZ3aV3qBDSAO+yhRVom8nllZdKIL7VSqYxngRLHwuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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