SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ae8614c6acf43cdb1357078cce6913ce1258491e4831ad10c1ffd4273f7f3526' 
  AND token = '5o+WeFRAnVl7mkG31R0NNF5++8g8txekVdW5CXwYDEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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