SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84bf467bdb7fcc2b4688a0446ff98e221a396ed51c168a83bfef87759441db60' 
  AND token = 'C2CUwHMx5EddcgXkI2l7urRKZQo8u0T+AMH/z9DuGPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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