SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c24a5373e9c3feff933979037c2762ed723a1ae4b0923cf1d0ddaae479754b01' 
  AND token = 'p3v5IPITnjM2N8tHPdKx+9F/wpBzbkkUMyxwF0ona0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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