SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '723c6bf354174dc2a79306436638cfcb8a23495ceb40abd2dad96e2131b8aba3' 
  AND token = 'uD1cGaAhZk5upCykRTM8rvP3JO8ezjQyypFETXBBSKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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