SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc7556dc4e308dfdec9e61d45eba48d779f32c595c416bef096da4fd0e238cdf' 
  AND token = 'LJSSdw2Mx0INNZvKB9/GXO/PTwTiYWpdqXhv0GCyS7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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