SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b664de0c41bfe1d67d9921f7fd52c78e702f753bb3a255f71533453188bdd1b' 
  AND token = '/Mkve/6XYIPEUDoFFqyHuIZ4I5Ck4enqhaGLN6K28jI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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