SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '952e0e56633162ab3ad97450a8d538a00f24d6324d5284b3e1726da7a2aa677c' 
  AND token = 'YIZKadKIVJSLkmfpsGK2ZOvSuZ2jgrm0Xm/p93w0UF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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