SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4c75a7c7e366d26b390fb40408460f0428a8df60506836af2111f30b8c4108a2' 
  AND token = 'ZZfNvasPmfdTKwb7bd+8Ygoh9lGrC/KcPCQalSL4mQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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