SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c90a5ec77f563d44ff75879b4bb40351d27c9785b12375e9e060668fb8b49008' 
  AND token = 'M3Y79Hk83E4Gp5CIkIJ73v1z5RvSuuFxfKUpsdcFHnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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