SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f40b70c4bc7c185105ea844336a5bd6c550e5fff63abe11a97b2a6c9e7d836ea' 
  AND token = 'QukS685WqY0PUuydhTy53qDICPbLvlkFuAIrmHFH+Vg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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