SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec91f584359a11b8f2e977a9c67163048ac29a2c0ab383cb9315a40f1730efb7' 
  AND token = 'XboXk6b4rDZFDhRn4jUWpf2zYBSEp8/Uz+fXF2PVhHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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