SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce1e3fb9032908af6ff85e38a99dba2274c7d74a23f356dd305d6641a4f9e40a' 
  AND token = 'j2gAFpbVweIm2BDuD5KOJubPu4eI8dXGZ5h2ZUXYrNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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