SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc85b096cded00136e271e80f330313e4bd8b7f60c5a282d23531c0dfa341a48' 
  AND token = 'Q8iHlBI/Qhl0DZZAnnCWSL3eQ6S12Eb9hoU/IgadX0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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