SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aff18e96e2326e630ab03b3d14871b646309d0c824f24b315821f58afd705dc4' 
  AND token = 'IjIsBjmLrHzgwKHlezGUQyXAyMbijaiOpMKClEOAoCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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