SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cdb1a336132cb226dad7ef4667b87e582631bd2212e289888c8f0653c4a386f1' 
  AND token = 'ToGMKvRLpsx/4HZupC6LAQ+nFNZFJfKvlTtCozasVkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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