SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b63d8eb17d7ec99bb97c746f4b1b26d42f954cbbcb5b25dd974929d008a7534c' 
  AND token = 'gRN+oErtraecUBpFfewXbMnYIOuF1uLN6ErE44EP9nA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}