SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95ee79c395c2cb411bea673bfee61188b539f7427d3862bbc46531e0353c51eb' 
  AND token = 'ksNAqiLsUfruCOU5Z/ScPYxpjuEluAwLZkwClSueoFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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