SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e26759e2b1768a177d8b93fe535e9bb8b35aa16ccd1536a0c1a3b24ef4e9de81' 
  AND token = '5GOhPw1x+nOTqxiJG97B026VphBK9wnzjD2rst+vz5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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