SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9790335c1064b10db163392b167454cf4f8e03498ac53c7ed70437e225cf690' 
  AND token = 'o0lWvx49QkTCKgXPyHyoXJllFgUkjZgZKNDpErhfRHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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