SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5ecea452e9fd9b0725294b1e35ae8189f3fd7a0a8527e4342fc9c2c5a39657a' 
  AND token = 'eLJ9+26JAjIRYgO7QYSU7Dt+R+tnGy629irjhPovWgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}