SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '298938c180528ce1ba84f258e665c94a3e86aa9e879d5312292dacdc4f1d159d' 
  AND token = 'sn+piCPd+uknI34JGj696ERn2A4Cl8bG8EIQ87NlZyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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