SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '981b2ea1352d907b1bb6f0135a448ae25bd2f0bff5b63cc579d22725efe59b2d' 
  AND token = 'vwplYdht2ZiE1wiq7qm1LdFTOag918lWCrNp8slsi9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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