SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb846c5195747c74ac1cb0ec080e18a4867837fdb486aa0c1e4efb18c2ced96e' 
  AND token = 'kJ5dw/QKPiDDKiANjU1o/6b6oadblJouqgH4OJ2qlVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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