SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae05c166afde2fc4d2350f82cd64385213dc5f189047ae9e1bd7129453366735' 
  AND token = '+Kqsgb/mYJcn/NcnzogqHvlQwM3EqJ88Dmb02amH+W8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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