SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d2d30b3d20828d7a51c14802c23e685c6cb54312f65fb768b6cb03727cec217' 
  AND token = 'hGA61+hJn642QLGe9mXLNm5rWQHarR8MQLxcFppPnU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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