SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '262774d37eecb6128928f622d238c20f02e9b05ebfbe08ae4a240cc9d383bdb5' 
  AND token = 't3vuVK/IflAz1kBSiWbnIRwRDiTgyYmKW6Fjlt5KmVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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