SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2e81efa58b2ea15283fd503df90651d5761cf6dde108084579cffd3a5c807ae' 
  AND token = 'lJMhjHkNFppD2hXOcEVz+0FHFskeBAgwF47dpKtdpfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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