SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4acf224ad306c471ab285355139cf487ca3f6299f1438cb0676fcda51295e04' 
  AND token = 'A9+KPS+3dHrBLwoUy+iO6bYZyq+jbFNla8uFQbg+/xA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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