SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '73bbd5acb9cf1684c75263bbc9563ca53a0943409bb971fe4085395e487e159a' 
  AND token = 'EQ5mG4AXpguHMibBSa6fJH41xVrTlDzwRW1vop8v978=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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