SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b0461acbfaa49dfe380be2194dee5d444485565faf22cf4fc9359b9db478e1f' 
  AND token = 'wuGGVqlN4GXrziEfsbTitJOGX2R+Z2L2zGus/JKjkmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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