SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a52be2ec5bca050ae49ca86472811374b66c2a3ef4bbdb437f8e956435a2dddf' 
  AND token = 'GlmA1SLiXsGtYvidz9ius/eFjljXp47OJ1N2Ushvshk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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