SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8415ded73c158d0e78d3a5757f262a44924053eac3bf2a50407a2d296a77373e' 
  AND token = 'Ko/SMKua2CRW3YWAdevneHsTgGeqWtceucLQhIMpsug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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