SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '697a668ee828ac511f78ab26ea4c9f2624bd06f7bb1095b2d42c7ef6f896ac4b' 
  AND token = 'zWftgMaokDdq0lwv1dkYT1slffkYTLc7tvoQUjSEnmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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