SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feac7121b4ff2905ab90c280301b995b288359fca49dff49ae2c1f7d772a8cf8' 
  AND token = '/BMq5KVXb/WGF2jpCdCTfYRtaHXimBsHHsU7GM0rmvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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