SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0501128aa430b858a0fe683224cdd3496822def847f127bf1bd8901891a11a16' 
  AND token = 'ndoweIfVGi5cmMjy56d5i8ziKjf2JgjPsO53wcFwGC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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