SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ce5b026af569094cfe7f550b5922201a382491377977cc162146209d48864647' 
  AND token = 'aflbhjy6s1+mGdUphsZZtxcVjB1fHoPq7dqXDLIT7qI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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