SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f368aba9c7d1b3c3a16ae9b7d13bd4fc64458cce9f2499f1ac461733e7a09dd8' 
  AND token = '3ErfZK6wsH/oTKJG/wJ7qrGxMOa7s3pl0sqFlL59+hg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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