SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f12e704c3dcc083afbd611bd95737d26ad699cc6224d3fd8b808bc524749c1a0' 
  AND token = 'SohHF5k+WyXKmBXxCqemvaqxWFxv3Q38eSFJkiKGd70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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