SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c06eaee2a09d323f961d0154b911030d53226ff9abc6253721298d97f237464c' 
  AND token = 'UfVGrjZGn+gGUq6b3lvJokSPDozVQuw7ev7bBsII3GM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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