SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5a0a8520d0a145bdd47434eda39c0edabea1eae1975bcd060fbf3e2d5e95d28' 
  AND token = 'HL7nTShAVFQoVTMNZHzqGHofvJJjoj9qR6X9202pdGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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