SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '714ed5c87dc0166f0ec3a4c1e542cba99595d6d88574065081e5c1260312193b' 
  AND token = 'EDnFZy63NSWBfFG44orXfn1Jv/hPudqCy0JkgKJJwoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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