SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de950c0b863966e10d9854245aba125965e65386afbadc11286d619b183241c0' 
  AND token = 'P4AmN2v9YLeJXZOrv5ojue2DcoEsF1tGl05e96YS9Ps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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