SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b74a86b6d57f9d3eea2b1137500ba11b6dad4a4dae3326500d9cbfa4213064c' 
  AND token = 'r7XPwzf4f6meBdBPyHLYlIbEwijjAWerdHeZsKUucpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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