SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a627cf3d5a44d36a03ebcbdaf8ea608b07309a28340cc9729fb8420c56c7b0d6' 
  AND token = 'mFrXELPujR5gwm5T7HW8wFHm9k1QAkMr3xVgI0d4y08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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