SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1415ebb9ad4c8b7d618d2b0068a2f9aa09c3c819a945292e8f51ff6f788cf546' 
  AND token = 'vsNonQNEzbxw2VIUoS8chlj7PESDnFL96uTm982TVgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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