SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '14387d71fd8a2d59abae2699be25587a11d6071f7df61cb6de470d1bea8a0c14' 
  AND token = 'xDYKGZUBF0Jv6LBMoqzUt51I1ney/VNXU4/nG5PiuGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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