SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a80f8f2c86efa31d11e77bb56203df80f7ed46e454478c701756eddc4ead53a0' 
  AND token = 'AwJkycLDm1kn8zQX0/XnyJbrHg/YcCkExeXPUnHu1e0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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