SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a65c03680abdcb3ce0e7a247f7aaed92e0038d81c74274571b9474958e2c1f1d' 
  AND token = 'LZ2fKG1npFY6HSETyYvtU4oB2GsE61ihxSyRkhjHTvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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