SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edd3818655b4a649ede002443105e0a38abe29d075de1d3fe7f6b24a4ba0b648' 
  AND token = 'CoEtvpBSWss+STrbmcehHtZgRBc7MzyXRoYbu/4XxPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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